1. Field of the Invention
The present invention relates to an ultrasonic diagnostic apparatus capable of obtaining tissue movement information such as cardiac wall movement information, an ultrasonic image processing apparatus performing an imaging process by using the tissue movement information obtained by the ultrasonic diagnostic apparatus, a medical image diagnostic apparatus, and a medical image processing apparatus.
2. Description of the Related Art
In an ultrasonic diagnosis, a heartbeat or a fetus's movement state may be obtained in real time just by touching a body surface with an ultrasonic probe and the ultrasonic diagnosis may be repeated due to the reliability thereof. In addition, since the size of the system of the ultrasonic diagnostic apparatus is smaller than those of other diagnostic apparatuses such as an X-ray diagnostic apparatus, a CT diagnostic apparatus, and an MRI diagnostic apparatus, the ultrasonic diagnosis may be easily performed by disposing the ultrasonic diagnostic apparatus at a position on the side of the bed. For this reason, the ultrasonic diagnosis is a simple diagnosis method. The size of the ultrasonic diagnostic apparatus used in the ultrasonic diagnosis is different depending on the types of the functions thereof, and a small-sized ultrasonic diagnostic apparatus which is able to be carried by one hand is developed. Unlike the X-ray diagnosis, the ultrasonic diagnosis has no influence of a radiation exposure, and hence the ultrasonic diagnosis may be used for the obstetrics and gynecology or the home medical treatment, and the like.
Generally, in the diagnosis of the body tissue, it is very important to objectively and quantitatively evaluate the function of the body tissue such as a myocardium of a heart. Recently, a quantitative evaluation method has been proposed which obtains image data of a heart using the above-described ultrasonic diagnostic apparatus and performs a quantitative evaluation based on the image data. For example, in Jpn. Pat. Appln. KOKAI Publication No. 2003-250804, a method is proposed which obtains movement information such as displacement or strain of a tissue by tracking a speckle pattern of an image. This method is to perform a pattern matching process using the speckle pattern of the image, and is called a Speckle Tracking Process. Recently, a three-dimensional tracking process for three-dimensional volume data is able to be performed in addition to a tracking process for a two-dimensional tomographic image. As a detailed example, when a myocardium of a heart is evaluated, volume data for each cardiac time phase is obtained by transmitting an ultrasonic wave to the heart by using a three-dimensional ultrasonic diagnostic apparatus. In addition, when a pattern matching process using a three-dimensional speckle tracking process is performed, it is possible to obtain displacement of an endocardium and an epicardium for each cardiac time phase. Then, on the basis of the displacement of the endocardium and the epicardium at each time phase, it is possible to obtain strain or velocity of the myocardium at each time phase. By obtaining the wall movement information, the wall movement of the myocardium is evaluated.
However, the wall movement parameter such as strain or velocity obtained in the known three-dimensional tracking process is a two-dimensional parameter, and the three-dimensional wall movement information obtained by the three-dimensional tracking process is converted into two-dimensional information. For this reason, the three-dimensional wall movement information calculated by the three-dimensional tracking process is not sufficiently provided to a user.